Of the 640 species of birds present in Australia in 1750, 1.4% are extinct, 6.7% are near threatened. This is lower than in many other parts of the world, which is partly explained by the environmental history within which Australian birds evolved, initially without people as the continent drifted north and away from other Gondwanan fragments. The trend in the status of threatened species since then has been exponential, based on patterns of environmental change and historical records that allowed estimation of the status of all Australian species at 50 year intervals since 1750. Island faunas have been the worst affected, but the mainland fauna is under increasing pressure, even if intensive conservation management has prevented some extinctions. We predict that by 2050 nearly 20% of Australian species will be at least near threatened, even if existing conservation management continues to be applied. This is because, although most threatened species have survived long enough to benefit from recent conservation initiatives, they now face rapid climate change and the residual effects of habitat fragmentation and degradation.